The present invention relates to a method for removing entrained, dense particulate materials from an elongated body of less dense fibrous materials. More specifically, the present invention relates to a method and apparatus for removing entrained balls from yarns being transported by a moving fluid stream.
Synthetic fibers are commonly produced by extruding molten polymer through a spinneret. Obviously, the filaments thus produced are smooth and lack the bulk and hand possessed by natural materials such as wool. On order to produce yarns which have properties approximating those of wool or other natural materials, it is common practice to subject the extruded filaments to a texturing process. This can be accomplished by a variety of procedures known in the art, such as stuffer-box crimping, false twist texturing and fluid jet texturing. One particularly effective procedure involves contacting the fibrous materials with a high velocity fluid stream in a turbulent zone and at an elevated temperature. The turbulence imparted to the fiber materials produces crimps which give the fiber a textured bulky appearance. It has more recently been found that improved texturing can be accomplished by passing the yarn from the turbulent zone through a chamber which contains a plurality of discrete particulate elements, such as balls. These balls exert a force on the yarn to produce a wad which extends through the chamber. The yarn wad can then be passed into the inlet end of an elongated tube provided with one or more openings intermediate the ends thereof. A fluid, such as air, is passed through the tube toward the inlet end, with a substantial quantity of the fluid being vented through the openings. The fluid thus exerts a retarding force which tends to prevent breakup of the yarn wad until the yarn has been cooled. Usually the wad is broken up and a single yarn withdrawn adjacent the openings in the tube. The cooled textured yarn is then withdrawn from the outlet end of the tube.
During startup, which of course requires stringing of the yarn through the various apparatus and formation of the wad, it is conventional practice to introduce fluid into the tube downstream of the openings in the tube and in a direction so that the flow of the fluid through the tube will be toward the outlet end and such fluid will act to aspirate the yarn through the tube. This aspirating fluid may be introduced into the tube itself as part of the operation by an appropriate valve system which then reverses the flow toward the inlet end after the operation has become stabilized, or, as is the usual case, the aspirator is a separate flexible tube, usually hand-held by an operator. In any event, during the startup operation and until the wad has formed and the operation has become stabilized, it is conventional practice to pass the aspirated yarn to a waste area or bin. Although the startup time is usually of relatively short duration, the cumulative startups necessitated by restringing of the apparatus due to breaks or other malfunctions becomes quite significant in commercial operations. Consequently, significant amounts of yarns are passed to waste, which is a saleable item. However, it has been found that a significant number of the balls are entrained in the yarn carried by the fluid stream while the wad is being formed and before the operation has become stabilized. Accordingly, these balls are carried along the flow line, drop out at various points along the flow line, and at times are carried over into the waste. Irrespective of where the balls end up, there is obviously a significant loss of the balls, which is a significant cost factor, but, in addition, natural separation of the balls from the waste yarn, dropping of the balls on the floors, and the carryover of the balls into the waste, which is sold for various purposes, all constitute safety hazards.
It is therefore an object of the present invention to provide an improved method and apparatus for separating entrained, dense particulate materials from an elongated body of less dense fibrous materials. Another and further object of the present invention is to provide an improved method for removing entrained, dense particulate materials from an elongated body of less dense fibrous materials and retrieving the particulate materials. A further object of the present invention is to provide a method and apparatus for removing entrained dense particulate materials from a synthetic yarn being transported by a moving fluid stream. Another object of the present invention is to provide an improved method and apparatus for removing small balls from a synthetic fibrous material being transported by a moving fluid stream. A still further object of the present invention is to provide an improved method and apparatus for removing balls from a synthetic yarn being transported by a fluid stream, which balls have become entrained in the yarn during the texturing of said yarn. These and other objects and advantages of the present invention will be apparent from the following description when read in conjunction with the drawings.